What the Malaysian government doing about th Africans and Nigerians involved in all kind of illegal activities?

What the Malaysian government doing about the Africans and Nigerians involved in all kind of illegal activities? Many articles was published in the local newspapers about the so called African students ( Old Buffaloes) nuisance in Malaysia. Most of them look so old (above 40 and 50 above) but bribing the Immigration Department and Higher Education Department obtaining illegal student visas and all of them are found sitting at bus stops, super markets, cyber cafes but suppose to be in colleges involved in all type of illegal activities. Daily they are found sitting at beer shops consuming beers with Filipino widows and divorcees and maids at Taman Wawasan Puchong, Pusat Bandar Puchong, Pusat bandar Puteri and enjoying life like dukes. The Filipino women and also local widows and divorcees in exchange for sex pay rent for the AFRICANS and Nigerians to live in high class condos. The Africans also drive expensive cars which are obtained through various scams in the internet. Why the ruling government or state government still allowing the Africans to enter daily in Malaysia?